Growth kinetics supported model catalyst

Supported model catalysts are frequently prepared by thermally evaporating metal atoms onto a planar oxide surface in UHV. The morphology and growth of supported metal clusters depend on a number of factors such as substrate morphology, the deposition rate, and the surface temperature. For a controlled synthesis of supported model catalysts, it is necessary to monitor the growth kinetics of supported metal... 

Recently, we reported detailed descriptions of hydrocarbon chain growth on supported Ru catalysts (7,8) we showed that product distributions do not follow simple polymerization kinetics and proposed a diffusion-enhanced olefin readsorption model in order to account for such deviations (7,8). In this paper, we describe this model and show that it also applies to Co and Fe catalysts. Finally, we use this model to discuss a few examples from the literature where catalyst physical structure and reaction conditions markedly influence hydrocarbon product distributions. 

The aim of this study was to develop a kinetic model for the reduction of a supported chromia catalyst. The reduction rate data was examined by various methods and typical kinetic models were tested. Based on the information obtained, the nucleation/nuclei growth models were investigated more closely and derived in a revised form. 

In addition to the patent literature available on the production of BR in the gas-phase there is some scientific literature which mainly refers to the modeling of reaction kinetics. Details on the experimental procedure for the determination of the macroscopic kinetics of the Nd-mediated gas-phase polymerization of BD in a stirred-tank reactor are reported [568,569]. Special emphasis is given to video microscopy of individual supported catalyst particles, individual particle growth and particle size distribution (PSD). These studies reveal that individual particles differ in polymerization activity [536,537,570,571]. Reactor performance and PSD are modeled on the... 

The last part of this chapter deals with coordination polymerization kinetics and mechanism, mathematical models at different scales, as well as some analyses on the supported catalyst particle breakup and growth. 

Hence, video microscopy analysis is not only a tool for screening of supported catalysts [66] but is also useful for the assignment of a given (industrial) catalyst system to the appropriate kinetic profile and the describing mathematical model. Finally, it is possible to explain certain aspects of crystalline homopolymer growth versus amorphous copolymer growth and the comonomer effect [63-66]. 

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